1/*-
2 * Copyright (c) 2000 Doug Rabson
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD$
27 */
28
29#ifndef _SYS_TASKQUEUE_H_
30#define _SYS_TASKQUEUE_H_
31
32#ifndef _KERNEL
33#error "no user-servicable parts inside"
34#endif
35
36#include <sys/queue.h>
37#include <sys/_task.h>
38#include <sys/_callout.h>
39
40struct taskqueue;
41struct thread;
42
43struct timeout_task {
44	struct taskqueue *q;
45	struct task t;
46	struct callout c;
47	int    f;
48};
49
50/*
51 * A notification callback function which is called from
52 * taskqueue_enqueue().  The context argument is given in the call to
53 * taskqueue_create().  This function would normally be used to allow the
54 * queue to arrange to run itself later (e.g., by scheduling a software
55 * interrupt or waking a kernel thread).
56 */
57typedef void (*taskqueue_enqueue_fn)(void *context);
58
59struct taskqueue *taskqueue_create(const char *name, int mflags,
60				    taskqueue_enqueue_fn enqueue,
61				    void *context);
62int	taskqueue_start_threads(struct taskqueue **tqp, int count, int pri,
63				const char *name, ...) __printflike(4, 5);
64int	taskqueue_enqueue(struct taskqueue *queue, struct task *task);
65int	taskqueue_enqueue_timeout(struct taskqueue *queue,
66	    struct timeout_task *timeout_task, int ticks);
67int	taskqueue_cancel(struct taskqueue *queue, struct task *task,
68	    u_int *pendp);
69int	taskqueue_cancel_timeout(struct taskqueue *queue,
70	    struct timeout_task *timeout_task, u_int *pendp);
71void	taskqueue_drain(struct taskqueue *queue, struct task *task);
72void	taskqueue_drain_timeout(struct taskqueue *queue,
73	    struct timeout_task *timeout_task);
74void	taskqueue_drain_all(struct taskqueue *queue);
75void	taskqueue_free(struct taskqueue *queue);
76void	taskqueue_run(struct taskqueue *queue);
77void	taskqueue_block(struct taskqueue *queue);
78void	taskqueue_unblock(struct taskqueue *queue);
79int	taskqueue_member(struct taskqueue *queue, struct thread *td);
80
81#define TASK_INITIALIZER(priority, func, context)	\
82	{ .ta_pending = 0,				\
83	  .ta_priority = (priority),			\
84	  .ta_func = (func),				\
85	  .ta_context = (context) }
86
87/*
88 * Functions for dedicated thread taskqueues
89 */
90void	taskqueue_thread_loop(void *arg);
91void	taskqueue_thread_enqueue(void *context);
92
93/*
94 * Initialise a task structure.
95 */
96#define TASK_INIT(task, priority, func, context) do {	\
97	(task)->ta_pending = 0;				\
98	(task)->ta_priority = (priority);		\
99	(task)->ta_func = (func);			\
100	(task)->ta_context = (context);			\
101} while (0)
102
103void _timeout_task_init(struct taskqueue *queue,
104	    struct timeout_task *timeout_task, int priority, task_fn_t func,
105	    void *context);
106#define	TIMEOUT_TASK_INIT(queue, timeout_task, priority, func, context) \
107	_timeout_task_init(queue, timeout_task, priority, func, context);
108
109/*
110 * Declare a reference to a taskqueue.
111 */
112#define TASKQUEUE_DECLARE(name)			\
113extern struct taskqueue *taskqueue_##name
114
115/*
116 * Define and initialise a global taskqueue that uses sleep mutexes.
117 */
118#define TASKQUEUE_DEFINE(name, enqueue, context, init)			\
119									\
120struct taskqueue *taskqueue_##name;					\
121									\
122static void								\
123taskqueue_define_##name(void *arg)					\
124{									\
125	taskqueue_##name =						\
126	    taskqueue_create(#name, M_WAITOK, (enqueue), (context));	\
127	init;								\
128}									\
129									\
130SYSINIT(taskqueue_##name, SI_SUB_CONFIGURE, SI_ORDER_SECOND,		\
131	taskqueue_define_##name, NULL);					\
132									\
133struct __hack
134#define TASKQUEUE_DEFINE_THREAD(name)					\
135TASKQUEUE_DEFINE(name, taskqueue_thread_enqueue, &taskqueue_##name,	\
136	taskqueue_start_threads(&taskqueue_##name, 1, PWAIT,		\
137	"%s taskq", #name))
138
139/*
140 * Define and initialise a global taskqueue that uses spin mutexes.
141 */
142#define TASKQUEUE_FAST_DEFINE(name, enqueue, context, init)		\
143									\
144struct taskqueue *taskqueue_##name;					\
145									\
146static void								\
147taskqueue_define_##name(void *arg)					\
148{									\
149	taskqueue_##name =						\
150	    taskqueue_create_fast(#name, M_WAITOK, (enqueue),		\
151	    (context));							\
152	init;								\
153}									\
154									\
155SYSINIT(taskqueue_##name, SI_SUB_CONFIGURE, SI_ORDER_SECOND,		\
156	taskqueue_define_##name, NULL);					\
157									\
158struct __hack
159#define TASKQUEUE_FAST_DEFINE_THREAD(name)				\
160TASKQUEUE_FAST_DEFINE(name, taskqueue_thread_enqueue,			\
161	&taskqueue_##name, taskqueue_start_threads(&taskqueue_##name	\
162	1, PWAIT, "%s taskq", #name))
163
164/*
165 * These queues are serviced by software interrupt handlers.  To enqueue
166 * a task, call taskqueue_enqueue(taskqueue_swi, &task) or
167 * taskqueue_enqueue(taskqueue_swi_giant, &task).
168 */
169TASKQUEUE_DECLARE(swi_giant);
170TASKQUEUE_DECLARE(swi);
171
172/*
173 * This queue is serviced by a kernel thread.  To enqueue a task, call
174 * taskqueue_enqueue(taskqueue_thread, &task).
175 */
176TASKQUEUE_DECLARE(thread);
177
178/*
179 * Queue for swi handlers dispatched from fast interrupt handlers.
180 * These are necessarily different from the above because the queue
181 * must be locked with spinlocks since sleep mutex's cannot be used
182 * from a fast interrupt handler context.
183 */
184TASKQUEUE_DECLARE(fast);
185int	taskqueue_enqueue_fast(struct taskqueue *queue, struct task *task);
186struct taskqueue *taskqueue_create_fast(const char *name, int mflags,
187				    taskqueue_enqueue_fn enqueue,
188				    void *context);
189
190#endif /* !_SYS_TASKQUEUE_H_ */
191